Altered salivary profiles in adolescents with dental caries and central obesity: a cross-sectional study

Abstract

Objectives: To explore the associations among salivary profiles, dental caries, and central obesity in adolescents. Methods: This cross-sectional study involved 184 adolescents aged 12–15 years. Anthropometric measurements and dental examinations were conducted. The participants were sex- and age-matched and classified into four groups: 1) normal waist-to-height ratio (WHtR) without caries (NW+NC), 2) high WHtR and without caries (HW+NC), 3) with normal WHtR and caries (NW+C), or 4) high WHtR with caries (HW+C). Unstimulated and stimulated saliva samples were collected to assess salivary flow rates, pH, and buffering capacity. Salivary biomarkers, including lipoprotein-associated phospholipase A2 (Lp-PLA2), secretory phospholipase A2 group IIA (sPLA2-IIA), interleukin-6, and serum amyloid A, were quantified using enzyme-linked immunosorbent assay (ELISA). Quantitative real-time polymerase chain reaction (qPCR) was used to measure Streptococcus mutans and total bacterial load. Results: Significantly different salivary Lp-PLA2 levels, sPLA2-IIA output, total bacterial load, Streptococcus mutans abundance, and flow rates were observed among the four groups. The NW+C, HW+NC, and HW+C groups had significantly higher salivary Lp-PLA2 levels and significantly lower salivary flow rates than the NW+NC group. The HW+C group had a significantly lower salivary sPLA2-IIA output and higher total salivary bacterial load than the NW+C group. Conclusions: Both dental caries and central obesity are associated with elevated Lp-PLA2 and decreased salivary gland secretory function. Adolescents with both conditions showed decreased salivary sPLA2-IIA output and increased salivary bacterial load, which may indicate compromised oral antimicrobial status that warrants further investigation. Clinical significance: Observed changes in salivary profiles may offer preliminary insights into the mechanisms linking obesity and oral health, potentially informing the development of more tailored oral health programs for children and adolescents with obesity.